Russian Journal of Dentistry

BACKGROUND: Recent studies have revealed a rather high prevalence of electric potential differences between metallic inclusions in the oral cavity, including in the presence of metal-containing orthodontic appliances. Due to the lack of precise information in official sources on the composition of structural materials used in orthodontic appliances and the difficulty of theoretical calculation of electrochemical contact potentials, an analysis of the alloy composition of appliances from different manufacturers is necessary.

AIM: To determine and analyze the elemental composition of metal-containing components of modern orthodontic appliances (brackets, archwires, implants) from various manufacturers available on the Russian market using energy-dispersive spectrometry.

METHODS: The sample comprised 16 metal-containing components of domestic and imported orthodontic appliances used in Russia: 8 orthodontic archwires, 5 bracket samples, and 3 orthodontic implants. Elemental analysis was performed using an energy-dispersive X-ray detector (EDX) in a dualbeam scanning electron microscope FEI Helios NanoLab 660 (FEI Company, USA). Quantitative data (element content, weight %) are presented as arithmetic means from three measurement points per sample. Statistical comparison was not performed due to the descriptive nature of the study.

RESULTS: This observational study (n = 16) revealed significant diversity in the composition of widely used metal-containing orthodontic structures (12 metallic elements, including iron, titanium, chromium). Notably, high nickel (up to 13.9 wt%) and aluminum (up to 10.9 wt%) content was detected for the first time in some implant samples.

CONCLUSION: The problem of controlling the electrochemical activity of metallic orthodontic appliances remains relevant due to the high prevalence of electric potential differences in the oral cavity of patients wearing such devices. Contact between dissimilar metals (brackets, archwires, implants) may trigger electrochemical reactions. The obtained data substantiate the need for a responsible, individualized selection of orthodontic appliances and consideration of their elemental composition during treatment planning. Study limitations: small sample size (n = 16).

BACKGROUND: Despite the widespread adoption of CAD/CAM technologies for occlusal splint fabrication, the degree of agreement between virtually calculated occlusal contacts and the actual clinical contact pattern remains insufficiently investigated. The accuracy of occlusal transfer may be influenced not only by digital design algorithms but also by CAM manufacturing stages, post-processing procedures, and clinical adaptation of the appliance. Quantitative criteria for comprehensive evaluation of occlusal contact reproducibility throughout all stages of the digital workflow are still lacking.

AIM: To evaluate the accuracy of occlusal contact transfer in digitally designed occlusal splints by sequentially comparing virtual data with the geometry of the fabricated devices and clinical contacts in the oral cavity.

METHODS: A cross-sectional comparative clinical and laboratory study was conducted, including 20 clinical cases. For each case, two occlusal splints were fabricated (Avantis 3D and Exocad), totaling 40 appliances. Original STL models were compared with STL models of the splints after milling and scanning, and virtual contact maps were compared with clinical occlusal contacts recorded using 8- and 40-μm articulating film. Geometric deviations between CAD and CAM models were assessed using the Hausdorff distance, with independent verification in GOM Inspect. Localization and intensity of occlusal contacts were additionally analyzed according to functional zones of the dental arch. Statistical analysis was performed using the Pearson's chi-square test and Cohen's kappa coefficient.

RESULTS: Virtual contact maps of Avantis 3D and Exocad coincided in 16 of 20 paired comparisons (80%). During clinical validation, the agreement between virtual and actual contacts was 70% for Avantis 3D and 85% for Exocad; no statistically significant differences were found between the systems (χ² = 1.80; p = 0.180), and the kappa coefficient was κ = 0.41. The most pronounced discrepancies in contact localization were observed in the anterior segment of the dental arch, whereas the highest reproducibility was maintained in the molar segments. Analysis of contact intensity showed that the lowest agreement indices were recorded in the caninepremolar segments. According to Hausdorff analysis, when virtual and clinical contacts agreed in ≥ 80% of cases, maximum deviations in the occlusal zone did not exceed 50–70 μm, whereas in cases of clinical discrepancies, the 95th percentile was 132 ± 24 μm, exceeding the threshold value of 100 μm.

CONCLUSION: The accuracy of occlusal contact transfer in digitally fabricated splints is determined by the combined influence of CAD design, CAM manufacturing, and clinical implementation stages. The proposed comprehensive approach, integrating clinical validation, zonal contact analysis, and Hausdorff-based metric assessment, enables objective quality control of the digital protocol and identification of error accumulation stages. Study limitations include the relatively small sample size and single-center design, warranting further validation in larger clinical cohorts.

BACKGROUND: The accuracy of cephalometric diagnostics in prosthodontic dentistry is directly determined by the reproducibility of the mandibular position during lateral cephalogram acquisition. In clinical practice, two reference positions are employed — the intercuspal position combined with centric relation (ICP-CR) and the retruded contact position (RCP), which is fixed using occlusal registration templates. However, a comparative assessment of the comparability of cephalometric parameters obtained in these positions remains insufficiently investigated, which underpins the relevance of the present study.

AIM: To conduct a comparative evaluation of skeletal, dental, and soft-tissue cephalometric parameters derived from lateral cephalograms obtained in the RCP and in the ICP-CR position, as well as to determine clinically significant differences between these positions, accounting for patient sex, age, and occlusion type.

METHODS: The study included cephalometric measurement data from lateral cephalograms of 50 patients, acquired in two positions: RCP and ICP-CR. Sagittal (ANB, WITS), vertical (SN/MP, FH/MP), dental (U1/APg, L1/APg), and soft-tissue (SnN'Pg', Jarabak ratio) parameters were analyzed. For each parameter, mean values, standard deviations, mean differences (Δ = ICP-CR − RCP), and mean absolute differences |Δ| were calculated. Paired t tests were performed, effect sizes were computed using Cohen's d, Pearson correlation coefficients were calculated, and subgroup analyses were conducted by sex, age, and occlusion type.

RESULTS: The most stable parameter was SN/MP (mean Δ = +0.6°; SD Δ ≈ 2.1°; d < 0.2). A statistically significant systematic difference was identified for the SnN'Pg' parameter (Δ = −1.4°; SD Δ ≈ 3.2°; t ≈ 2.59; p ≈ 0.014; d ≈ 0.44). For WITS, a trend toward significance was observed (Δ ≈ +0.5 mm; p ≈ 0.06–0.09). The greatest individual variability was recorded for FH/MP (individual Δ up to ± 7°) and L1/APg (SD Δ ≈ 3.8 mm). In the subgroup of patients with Class II occlusion, the most pronounced differences were observed for ANB (+0.9°), WITS (+1.5 mm), and SnN'Pg' (−2.1°; p < 0.05). In patients under 18 years of age, |Δ| for WITS and L1/APg was greater than in adults (p ≈ 0.04–0.07).

CONCLUSION: The RCP and ICP-CR demonstrate acceptable group-level reproducibility for the majority of skeletal cephalometric parameters. However, systematic differences in the softtissue profile (SnN'Pg') and substantial individual variability in FH/MP and dental parameters indicate the clinical significance of the choice of registration position, particularly in patients with Class II occlusion and hyperdivergent growth pattern. ICP-CR is recommended as the primary position for diagnostic evaluation, with repeat registrations indicated when discrepancies exceed 2–3°. A limitation of the present study is that the statistical analysis was performed using aggregated data, which constrains the application of more detailed analytical methods.

A key objective of modern implantology is to achieve an aesthetic result as close to natural as possible, which requires preserving or restoring the volume of hard and soft tissues around the implant. The absence of a periodontal ligament causes the tissues surrounding the implant to differ from those of an intact tooth, disrupting their nourishment. This leads to bone resorption and recession of the interdental papilla, which negatively affects the aesthetic outcome. Standard healing abutments, which have a round cross-section, do not always ensure predictable soft tissue healing, especially when a natural contour is required. The simplest and fastest method for fabricating a custom healing abutment is the combined laboratory-intraoral approach, which produces an abutment that precisely matches the gingival contour for subsequent prosthetic restoration.

This clinical case illustrates delayed implantation and the fabrication of custom healing abutments using CAD/CAM technology to achieve a natural-looking state of peri-implant soft tissues. A patient with secondary partial edentulism in the area of teeth 1.4 and 1.6, who required implant placement, had undergone a right-sided subantral augmentation procedure six months earlier. At the preoperative stage, custom healing abutment blanks and a surgical template were fabricated. The use of custom healing abutments in delayed implantation allows the formation of a natural soft tissue contour and reduces the number of clinical steps before final restoration.

The described technique appears effective for managing the healing of peri-implant tissues, ensuring a natural emergence profile in implant-supported restorations and optimizing treatment workflow.

Organ transplantation is currently one of the most effective methods of treating end-stage chronic diseases, significantly improving patient survival and quality of life. In particular, kidney transplantation is considered the “gold standard” for treating end-stage renal disease. However, its success depends largely on lifelong immunosuppressive therapy to prevent graft rejection, which is accompanied by both systemic and local complications.

Among these, oral lesions are particularly important. They result from both the direct effects of immunosuppressive drugs on oral tissues and microbiome and from reduced immune defenses, which promote infectious processes. The most common are viral, bacterial, and fungal infections, including herpes simplex virus, cytomegalovirus, and Candida spp.

Drug-induced complications include gingival hyperplasia, stomatitis, mucositis, and xerostomia. Of particular note is hypertrophic gingivitis associated with cyclosporine and other immunosuppressants, which can significantly impair quality of life and complicate oral hygiene. Reduced salivation also promotes pathogenic microbial growth and increases the risk of inflammatory disease.

This review is the first to systematize data on the effects of current immunosuppressive regimens on the oral cavity in kidney transplant recipients, considering the relationships between the type of medication, treatment duration, and dental complications, as well as the most common drug-induced oral lesions. The need for an interdisciplinary approach to managing this patient population is emphasized.

Reading this review will provide a comprehensive understanding of the mechanisms of dental complications in kidney transplant recipients, the effects of immunosuppressive drugs on oral tissues, and the importance of timely dental monitoring. Without this review, these relationships between drug therapy and oral health would not be presented in a systematic, clinically oriented manner.

The findings highlight the need for early diagnosis, regular dental monitoring, and an interdisciplinary approach to managing this patient population. The development of unified protocols for preventing and treating oral lesions in kidney transplant recipients is an important goal for future research and clinical practice.

Inflammatory and non-inflammatory periodontal diseases, as well as mechanical and chemical injuries to the oral mucosa and the connective tissue attachment of the tooth are common challenges in daily dental practice. Their local treatment typically involves adhesive pharmacological agents, most of which contain synthetic active or auxiliary ingredients. Moreover, not all drugs can remain on the oral mucosa or in the periodontal pocket for a prolonged period, providing sustained release and targeted delivery of active substances directly to the lesion site. A detailed understanding of the oral microbiome, the causes of its imbalance, and the composition and pharmacological effects of drugs used to restore the damaged periodontal complex is needed.

This review analyzes Russian and international research on modern approaches to the prevention, treatment, and restoration of periodontal tissues after injury, as well as the development of new strategies to address this problem. A search and analysis of publications was performed in the eLIBRARY.RU and PubMed databases on current methods for preventing and treating complications of periodontal tissues that arise during orthopedic treatment. Despite the wide range of drugs available on the domestic and international markets, the problem of periodontal disease remains relevant. The presence of synthetic substances in medications can accelerate stabilization of the pathological process, but does not exclude the risk of dysmicrobiocenosis. There is a need for a new, clinically effective Russian drug based on an adhesive pharmacological matrix that promotes rapid wound healing, prevents additional infection, and does not cause dysbiotic changes.